Table 2 The prognostic factors identified in the univariate and multivariate Cox regression models in the training cohort incorporating covariates identified by the smallest AIC value

 < =40

R

< 0.001

R

< 0.001

 < =60

1.328

1.148

1.537

< 0.001

1.231

0.006

 > 60

1.870

1.621

2.159

< 0.001

1.724

< 0.001

 White

R

< 0.001

R

< 0.001

 black

1.394

1.268

1.533

< 0.001

1.275

< 0.001

 Others^a

0.884

0.756

1.033

0.122

0.922

0.311

 Unmarried^b

R

< 0.001

R

< 0.001

 Married

0.666

0.616

0.719

0.751

 IDC

R

0.189

Not included

 ILC

0.916

0.801

1.048

0.202

 IDC and ILC

0.882

0.738

1.053

0.164

 I

R

< 0.001

R

< 0.001

 II

1.228

1.036

1.454

0.018

1.401

< 0.001

 III/IV

1.743

1.476

2.058

< 0.001

1.792

< 0.001

 HR+/HER2-

R

< 0.001

R

< 0.001

 HR−/HER2+

0.988

0.860

1.135

0.862

0.972

0.715

 HR+/HER2+

0.801

0.717

0.895

< 0.001

0.832

0.003

 HR−/HER2-

1.926

2.649

3.232

< 0.001

2.969

< 0.001

 T1

R

< 0.001

R

0.001

 T2

1.005

0.878

1.151

0.938

1.011

0.875

 T3

1.162

1.003

1.345

0.045

1.059

0.450

 T4

1.507

1.321

1.720

< 0.001

1.213

0.005

 N0

R

0.244

Not included

 N1

0.930

0.811

1.066

0.298

 N2

0.827

0.685

0.998

0.047

 N3

0.966

0.810

1.151

0.696

 No

R

< 0.001

R

< 0.001

 Yes

0.856

0.787

0.932

1.208

 No

R

< 0.001

R

< 0.001

 Yes

2.314

2.040

2.626

1.962

 No

R

< 0.001

R

< 0.001

 Yes

1.534

1.416

1.661

1.728

 No

R

< 0.001

R

< 0.001

 Yes

1.570

1.453

1.697

1.335

 No

R

< 0.001

R

< 0.001

 BCS

0.547

0.476

0.628

< 0.001

0.606

< 0.001

 Mastectomy

0.724

0.654

0.802

< 0.001

0.762

< 0.001

 No/Unknown

R

0.003

Not included

 Yes

0.885

0.818

0.958

 No/Unknown

R

< 0.001

R

< 0.001

 Yes

0.674

0.624

0.727

0.564